Biomechanical effects of different miniplate use on bone and miniplate systems in multiple mandible fracture: A finite element study

Purpose

The aim of this study is to evaluate the biomechanical efficiency of different miniplates in the treatment of multiple mandibula fractures.

Material and Method

Mandible, miniplates, and screws were modeled using the Solid Works v2015 (Dassault Systèmes, France) program, Subsequently two fracture lines were created on the right parasymphysis and angulus mandible. Models were divided into two main groups according to the plates used in the anterior fracture line: group A, 2 piece 4-hole-bar-I plate, and group B, ellipse plate. Each group was divided into five subgroups according to the plates used in the posterior fracture line (I, X, G, 3D, E) and 10 study models were created in total. Under three different biting forces (anterior, right, left), maximum von-Mises stresses seen on miniplates/screws, and Pmax/Pmin stresses seen in the cortically/cancellous bone were analyzed using the Ansys 16.2 software (ANSYS, Inc., USA). Data was visualized using a color distribution scale and interpreted.

Results

The highest von-Mises stress, seen in plates, was found in the I plate (353.82 MPa) at the angulus region of model A1. The highest Pmax and Pmin stresses, revealed in cortical bone, were found respectively in model A1 (181.63 MPa) and model B2 (115.01 MPa). The ideal results on plates were seen in models B3 and B5, in which E plates were used in the parasymphysis and G/E plates were used in the angulus region.

Conclusion

Grid and ellipse plates provide successful results and plate geometry is more critical than number in terms of stress distribution.